This spring, the Northwestern University Library Preservation Department curated the exhibit “Beyond the Book: The Changing Nature of Library Collections,” which highlights some of the Library’s rare and interesting objects that have received conservation attention in the past few years. In celebration of Preservation Week (April 26 – May 2, 2015), the blog will feature daily posts highlighting exhibit objects that posed some of the more complex research questions and interesting treatment decisions.

Charles Deering (1852-1927), for whom Deering Library was named, was an avid art collector and artist in his own right. In addition to collecting Spanish and Catalan art, Deering formed lasting friendships with many of the leading artists of his day and amassed a rich collection of portraits by close friends such as John Singer Sargent, Anders Zorn, Carl Larsson and Ramon Casas. Many of the paintings from Charles Deering’s personal collection were chosen to decorate Deering Library when it opened in 1933 and remain important works in the University Library’s collection.

The library’s painting of Erik Satie by Ramon Casas (El Bohemio, 1891) is one of our most requested paintings for loan and exhibition and recently underwent an extensive conservation treatment. Northwestern contracted with a local fine art conservator to perform the treatment.

In addition to repairs to the canvas, a varnish layer applied in the 1970s was removed. Polyvinyl acetate (PVA) was commonly used to varnish paintings in the 1970s. Over time, the PVA becomes gray and opaque and, as a result, the painting had taken on a hazy appearance. After conservators removed the PVA varnish, they noticed that there were still areas of the painting with a dull gray appearance. Sample testing and examination using a range of analytical tools, including scanning electron microscopy and Raman spectroscopy, indicated that these gray areas were likely a result of lead sulfate migrating up through the paint from the ground layer. The lead sulfate, which is insoluble in alcohol and other common conservation solvents, could not be removed. In order to minimize the visual disturbance of the lead sulfate, the decision was made to apply a thin wash of translucent pigment on top of the new Paraloid B-72 varnish layer in the gray areas. This is a reversible treatment that reflects the artist’s intent and allows the true colors of the painting to show through.

International press gather to document the Casas during exhibition installation.

The Frankfurt newspaper featured the painting in coverage of the exhibition.

The painting was featured last year in a groundbreaking exhibition at the Schirn Kunsthalle in Frankfurt. The exhibit, Esprit Montmartre: Bohemian Life in Paris around 1900, looked at Montmartre as a center of artistic life with a particular focus on individuals like Satie and Casas.

The Esprit Montmartre exhibition provided an opportunity to share El Bohemio with a large audience at an international venue after its recent conservation treatment. The exhibition also promoted Northwestern’s unique library collections in a global environment.

The Preservation Department is currently working on a comprehensive survey of other paintings in the collection in order to develop a plan for preserving Charles Deering’s legacy as an art collector.

This spring, the Northwestern University Library Preservation Department curated the exhibit “Beyond the Book: The Changing Nature of Library Collections,” which highlights some of the Library’s rare and interesting objects that have received conservation attention in the past few years. In celebration of Preservation Week (April 26 – May 2, 2015), the blog will feature daily posts highlighting exhibit objects that posed some of the more complex research questions and interesting treatment decisions.

Dr. Dale T. Mortensen (1939-2014) won the 2010 Nobel Prize for economics and is known for his work on labor economics and frictional unemployment. He taught at Northwestern from 1965 to 2011. After Dr. Mortensen’s death in 2014, his chalkboard was removed from the wall of his office on campus. It is included in his archive – along with documents, correspondence, computer files, and other personal effects – as a physical manifestation of his process.

Dale Mortensen’s chalkboard awaits treatment in the conservation lab after having been removed from his campus office.

Before the chalkboard could be stored in University Archives, a method needed to be devised to affix the chalk to the board so that the unbound media would not dust off. Special Collections Conservator Susan Russick researched various adhesives and application methods to determine the best one to keep the chalk in place. Funori, an adhesive made from Japanese seaweed, was chosen based on its good aging properties and the fact that it dries matte, thus retaining the visual aesthetic of the chalkboard.

Funori in three forms: dried seaweed, purified as a film, and rehydrated in solution.

To prepare the funori, 6 g of dried seaweed was rinsed and then soaked in 200 ml water overnight. The funori-water mixture was heated to just below simmer for about 90 minutes and strained through a silkscreen fabric. The resulting viscous liquid was dried on silicone coated Mylar, resulting in a translucent film. The funori film was stored dry and later reconstituted to a 0.5% solution by warming in deionized water.

A John Bunn Neb-U-lite EV™ machine, normally used for delivering medicine for respiratory ailments, was used to apply warm funori as a mist to the chalkboard. This very delicate application method was the only one found that did not disturb the fingerprints, erasure marks and smears of chalk.

In this brief video, Susan applies a layer of funori to one chalked letter using the nebulizer.

After treatment, Dr. Mortensen’s fingerprints and smudges are still visible on the surface of the chalkboard.

Multiple coats of funori were applied as a mist, each taking up to 15 hours to apply. The chalk still looks like just chalk – not shiny or slick – and without drip or brush marks. The chalk could still be removed if directly rubbed, but is now well adhered enough to tolerate the vibrations of being placed on a cart and moved for storage.

Chalkboard in custom-made box.

Detail of fall-away walls.

To prevent the chalk surface from being touched in storage, a special box was fabricated using Tycore® board, foam and cloth. The box grips the chalkboard around the aluminum edges using fold-away “load bearing” walls. Even if the lid warps a bit, it will not touch the surface of the chalkboard and Dr. Mortensen’s notes will remain intact for future scholars.